Re: [PATCH 0/15] Enable CXL PCIe port protocol error handling and logging

Bjorn Helgaas
2024-10-10T19:07:29Z

On Tue, Oct 08, 2024 at 05:16:42PM -0500, Terry Bowman wrote:
> This is a continuation of the CXL port error handling RFC from earlier.[1]
> The RFC resulted in the decision to add CXL PCIe port error handling to
> the existing RCH downstream port handling. This patchset adds the CXL PCIe
> port handling and logging.
>
> The first 7 patches update the existing AER service driver to support CXL
> PCIe port protocol error handling and reporting. This includes AER service
> driver changes for adding correctable and uncorrectable error support, CXL
> specific recovery handling, and addition of CXL driver callback handlers.
>
> The following 8 patches address CXL driver support for CXL PCIe port
> protocol errors. This includes the following changes to the CXL drivers:
> mapping CXL port and downstream port RAS registers, interface updates for
> common RCH and VH, adding port specific error handlers, and protocol error
> logging.
>
> [1] - https://lore.kernel.org/linux-cxl/20240617200411.1426554
> -1-terry.bowman@amd.com/

Makes life easier if URLs are all on one line so they still work.

> Testing:
>
> Below are test results for this patchset. This is using Qemu with a root
> port (0c:00.0), upstream switch port (0d:00.0),and downstream switch port
> (0e:00.0).
>
> This was tested using aer-inject updated to support CE and UCE internal
> error injection. CXL RAS was set using a test patch (not upstreamed).
>
> Root port UCE:
> root@tbowman-cxl:~/aer-inject# ./root-uce-inject.sh
> [ 27.318920] pcieport 0000:0c:00.0: aer_inject: Injecting errors 00000000/00400000 into device 0000:0c:00.0
> [ 27.320164] pcieport 0000:0c:00.0: AER: Uncorrectable (Fatal) error message received from 0000:0c:00.0
> [ 27.321518] pcieport 0000:0c:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), type=Transaction Layer, (Receiver ID)
> [ 27.322483] pcieport 0000:0c:00.0: device [8086:7075] error status/mask=00400000/02000000
> [ 27.323243] pcieport 0000:0c:00.0: [22] UncorrIntErr
> [ 27.325584] aer_event: 0000:0c:00.0 PCIe Bus Error: severity=Fatal, Uncorrectable Internal Error, TLP Header=Not available
> [ 27.325584]
> [ 27.327171] cxl_port_aer_uncorrectable_error: device=0000:0c:00.0 host=pci0000:0c status: 'Memory Address Parity Error'
> first_error: 'Memory Address Parity Error'
> [ 27.333277] Kernel panic - not syncing: CXL cachemem error. Invoking panic
> [ 27.333872] CPU: 12 UID: 0 PID: 122 Comm: irq/24-aerdrv Not tainted 6.11.0-rc1-port-error-g1fb9097c3728 #3857
> [ 27.334761] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> [ 27.335716] Call Trace:
> [ 27.335985] <TASK>
> [ 27.336226] panic+0x2ed/0x320
> [ 27.336547] ? __pfx_cxl_report_normal_detected+0x10/0x10
> [ 27.337037] ? __pfx_aer_root_reset+0x10/0x10
> [ 27.337453] cxl_do_recovery+0x304/0x310
> [ 27.337833] aer_isr+0x3fd/0x700
> [ 27.338154] ? __pfx_irq_thread_fn+0x10/0x10
> [ 27.338572] irq_thread_fn+0x1f/0x60
> [ 27.338923] irq_thread+0x102/0x1b0
> [ 27.339267] ? __pfx_irq_thread_dtor+0x10/0x10
> [ 27.339683] ? __pfx_irq_thread+0x10/0x10
> [ 27.340059] kthread+0xcd/0x100
> [ 27.340387] ? __pfx_kthread+0x10/0x10
> [ 27.340748] ret_from_fork+0x2f/0x50
> [ 27.341100] ? __pfx_kthread+0x10/0x10
> [ 27.341466] ret_from_fork_asm+0x1a/0x30
> [ 27.341842] </TASK>
> [ 27.342281] Kernel Offset: 0x1ba00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
> [ 27.343221] ---[ end Kernel panic - not syncing: CXL cachemem error. Invoking panic ]---
>
> Root port CE:
> root@tbowman-cxl:~/aer-inject# ./root-ce-inject.sh
> [ 19.444339] pcieport 0000:0c:00.0: aer_inject: Injecting errors 00004000/00000000 into device 0000:0c:00.0
> [ 19.445530] pcieport 0000:0c:00.0: AER: Correctable error message received from 0000:0c:00.0
> [ 19.446750] pcieport 0000:0c:00.0: PCIe Bus Error: severity=Correctable, type=Transaction Layer, (Receiver ID)
> [ 19.447742] pcieport 0000:0c:00.0: device [8086:7075] error status/mask=00004000/0000a000
> [ 19.448549] pcieport 0000:0c:00.0: [14] CorrIntErr
> [ 19.449223] aer_event: 0000:0c:00.0 PCIe Bus Error: severity=Corrected, Corrected Internal Error, TLP Header=Not available
> [ 19.449223]
> [ 19.451415] cxl_port_aer_correctable_error: device=0000:0c:00.0 host=pci0000:0c status='Received Error From Physical Layer'
>
> Upstream switch port UCE:
> root@tbowman-cxl:~/aer-inject# ./us-uce-inject.sh
> [ 45.236853] pcieport 0000:0c:00.0: aer_inject: Injecting errors 00000000/00400000 into device 0000:0d:00.0
> [ 45.238101] pcieport 0000:0c:00.0: AER: Uncorrectable (Fatal) error message received from 0000:0d:00.0
> [ 45.239416] pcieport 0000:0d:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), type=Transaction Layer, (Receiver ID)
> [ 45.240412] pcieport 0000:0d:00.0: device [19e5:a128] error status/mask=00400000/02000000
> [ 45.241159] pcieport 0000:0d:00.0: [22] UncorrIntErr
> [ 45.242448] aer_event: 0000:0d:00.0 PCIe Bus Error: severity=Fatal, Uncorrectable Internal Error, TLP Header=Not available
> [ 45.242448]
> [ 45.244008] cxl_port_aer_uncorrectable_error: device=0000:0d:00.0 host=0000:0c:00.0 status: 'Memory Address Parity Error'
> first_error: 'Memory Address Parity Error'
> [ 45.249129] Kernel panic - not syncing: CXL cachemem error. Invoking panic
> [ 45.249800] CPU: 12 UID: 0 PID: 122 Comm: irq/24-aerdrv Not tainted 6.11.0-rc1-port-error-g1fb9097c3728 #3855
> [ 45.250795] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> [ 45.251907] Call Trace:
> [ 45.253284] <TASK>
> [ 45.253564] panic+0x2ed/0x320
> [ 45.253909] ? __pfx_cxl_report_normal_detected+0x10/0x10
> [ 45.255455] ? __pfx_aer_root_reset+0x10/0x10
> [ 45.255915] cxl_do_recovery+0x304/0x310
> [ 45.257219] aer_isr+0x3fd/0x700
> [ 45.257572] ? __pfx_irq_thread_fn+0x10/0x10
> [ 45.258006] irq_thread_fn+0x1f/0x60
> [ 45.258383] irq_thread+0x102/0x1b0
> [ 45.258748] ? __pfx_irq_thread_dtor+0x10/0x10
> [ 45.259196] ? __pfx_irq_thread+0x10/0x10
> [ 45.259605] kthread+0xcd/0x100
> [ 45.259956] ? __pfx_kthread+0x10/0x10
> [ 45.260386] ret_from_fork+0x2f/0x50
> [ 45.260879] ? __pfx_kthread+0x10/0x10
> [ 45.261418] ret_from_fork_asm+0x1a/0x30
> [ 45.261936] </TASK>
> [ 45.262451] Kernel Offset: 0xc600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
> [ 45.263467] ---[ end Kernel panic - not syncing: CXL cachemem error. Invoking panic ]---
>
> Upstream switch port CE:
> root@tbowman-cxl:~/aer-inject# ./us-ce-inject.sh
> [ 37.504029] pcieport 0000:0c:00.0: aer_inject: Injecting errors 00004000/00000000 into device 0000:0d:00.0
> [ 37.506076] pcieport 0000:0c:00.0: AER: Correctable error message received from 0000:0d:00.0
> [ 37.507599] pcieport 0000:0d:00.0: PCIe Bus Error: severity=Correctable, type=Transaction Layer, (Receiver ID)
> [ 37.508759] pcieport 0000:0d:00.0: device [19e5:a128] error status/mask=00004000/0000a000
> [ 37.509574] pcieport 0000:0d:00.0: [14] CorrIntErr
> [ 37.510180] aer_event: 0000:0d:00.0 PCIe Bus Error: severity=Corrected, Corrected Internal Error, TLP Header=Not available
> [ 37.510180]
> [ 37.512057] cxl_port_aer_correctable_error: device=0000:0d:00.0 host=0000:0c:00.0 status='Received Error From Physical Layer'
>
> Downstream switch port UCE:
> root@tbowman-cxl:~/aer-inject# ./ds-uce-inject.sh
> [ 29.421532] pcieport 0000:0c:00.0: aer_inject: Injecting errors 00000000/00400000 into device 0000:0e:00.0
> [ 29.422812] pcieport 0000:0c:00.0: AER: Uncorrectable (Fatal) error message received from 0000:0e:00.0
> [ 29.424551] pcieport 0000:0e:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), type=Transaction Layer, (Receiver ID)
> [ 29.425670] pcieport 0000:0e:00.0: device [19e5:a129] error status/mask=00400000/02000000
> [ 29.426487] pcieport 0000:0e:00.0: [22] UncorrIntErr
> [ 29.427111] aer_event: 0000:0e:00.0 PCIe Bus Error: severity=Fatal, Uncorrectable Internal Error, TLP Header=Not available
> [ 29.427111]
> [ 29.428688] cxl_port_aer_uncorrectable_error: device=0000:0e:00.0 host=0000:0d:00.0 status: 'Memory Address Parity Error'
> first_error: 'Memory Address Parity Error'
> [ 29.430173] Kernel panic - not syncing: CXL cachemem error. Invoking panic
> [ 29.430862] CPU: 12 UID: 0 PID: 122 Comm: irq/24-aerdrv Not tainted 6.11.0-rc1-port-error-g844fd2319372 #3851
> [ 29.431874] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> [ 29.433031] Call Trace:
> [ 29.433354] <TASK>
> [ 29.433631] panic+0x2ed/0x320
> [ 29.434010] ? __pfx_cxl_report_normal_detected+0x10/0x10
> [ 29.434653] ? __pfx_aer_root_reset+0x10/0x10
> [ 29.435179] cxl_do_recovery+0x304/0x310
> [ 29.435626] aer_isr+0x3fd/0x700
> [ 29.436027] ? __pfx_irq_thread_fn+0x10/0x10
> [ 29.436507] irq_thread_fn+0x1f/0x60
> [ 29.436898] irq_thread+0x102/0x1b0
> [ 29.437293] ? __pfx_irq_thread_dtor+0x10/0x10
> [ 29.437758] ? __pfx_irq_thread+0x10/0x10
> [ 29.438189] kthread+0xcd/0x100
> [ 29.438551] ? __pfx_kthread+0x10/0x10
> [ 29.438959] ret_from_fork+0x2f/0x50
> [ 29.439362] ? __pfx_kthread+0x10/0x10
> [ 29.439771] ret_from_fork_asm+0x1a/0x30
> [ 29.440221] </TASK>
> [ 29.440738] Kernel Offset: 0x10a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
> [ 29.441812] ---[ end Kernel panic - not syncing: CXL cachemem error. Invoking panic ]---
>
> Downstream switch port CE:
> root@tbowman-cxl:~/aer-inject# ./ds-ce-inject.sh
> [ 177.114442] pcieport 0000:0c:00.0: aer_inject: Injecting errors 00004000/00000000 into device 0000:0e:00.0
> [ 177.115602] pcieport 0000:0c:00.0: AER: Correctable error message received from 0000:0e:00.0
> [ 177.116973] pcieport 0000:0e:00.0: PCIe Bus Error: severity=Correctable, type=Transaction Layer, (Receiver ID)
> [ 177.117985] pcieport 0000:0e:00.0: device [19e5:a129] error status/mask=00004000/0000a000
> [ 177.118809] pcieport 0000:0e:00.0: [14] CorrIntErr
> [ 177.119521] aer_event: 0000:0e:00.0 PCIe Bus Error: severity=Corrected, Corrected Internal Error, TLP Header=Not available
> [ 177.119521]
> [ 177.122037] cxl_port_aer_correctable_error: device=0000:0e:00.0 host=0000:0d:00.0 status='Received Error From Physical Layer'

Thanks for the hints about how to test this; it's helpful to have
those in the email archives. Remove the timestamps and non-relevant
call trace entries unless they add useful information. AFAICT they're
just distractions in this case.

> Changes RFC->v1:
> [Dan] Rename cxl_rch_handle_error() becomes cxl_handle_error()
> [Dan] Add cxl_do_recovery()
> [Jonathan] Flatten cxl_setup_parent_uport()
> [Jonathan] Use cxl_component_regs instead of struct cxl_regs regs
> [Jonathan] Rename cxl_dev_is_pci_type()
> [Ming] bus_find_device(&cxl_bus_type, NULL, &pdev->dev, match_uport) can
> replace these find_cxl_port() and device_find_child().
> [Jonathan] Compact call to cxl_port_map_regs() in cxl_setup_parent_uport()
> [Ming] Dont use endpoint as host to cxl_map_component_regs()
> [Bjorn] Use "PCIe UIR/CIE" instesad of "AER UI/CIE"
> [TODO][Bjorn] Dont use Kconfig to enable/disable a CXL external interface
>
> Terry Bowman (15):
> cxl/aer/pci: Add CXL PCIe port error handler callbacks in AER service
> driver
> cxl/aer/pci: Update is_internal_error() to be callable w/o
> CONFIG_PCIEAER_CXL
> cxl/aer/pci: Refactor AER driver's existing interfaces to support CXL
> PCIe ports
> cxl/aer/pci: Add CXL PCIe port correctable error support in AER
> service driver
> cxl/aer/pci: Update AER driver to read UCE fatal status for all CXL
> PCIe port devices
> cxl/aer/pci: Introduce PCI_ERS_RESULT_PANIC to pci_ers_result type
> cxl/aer/pci: Add CXL PCIe port uncorrectable error recovery in AER
> service driver

I had to look at the patches to learn that all the above only touch
drivers/pci, aer.h, and pci.h. Can you use the PCI subject line
conventions (e.g., "PCI/AER: ...") to make this more obvious? Almost
all already include "CXL", so I don't think we'd really lose any
information.

> cxl/pci: Change find_cxl_ports() to be non-static
> cxl/pci: Map CXL PCIe downstream port RAS registers
> cxl/pci: Map CXL PCIe upstream port RAS registers
> cxl/pci: Update RAS handler interfaces to support CXL PCIe ports
> cxl/pci: Add error handler for CXL PCIe port RAS errors
> cxl/pci: Add trace logging for CXL PCIe port RAS errors
> cxl/aer/pci: Export pci_aer_unmask_internal_errors()

Ditto here, and add something about CXL in the subject since this
doesn't export universally.

> cxl/pci: Enable internal CE/UCE interrupts for CXL PCIe port devices
>
> drivers/cxl/core/core.h | 3 +
> drivers/cxl/core/pci.c | 172 +++++++++++++++++++++++++++++++--------
> drivers/cxl/core/port.c | 4 +-
> drivers/cxl/core/trace.h | 47 +++++++++++
> drivers/cxl/cxl.h | 14 +++-
> drivers/cxl/mem.c | 30 ++++++-
> drivers/cxl/pci.c | 8 ++
> drivers/pci/pci.h | 5 ++
> drivers/pci/pcie/aer.c | 123 ++++++++++++++++++++--------
> drivers/pci/pcie/err.c | 150 ++++++++++++++++++++++++++++++++++
> include/linux/aer.h | 16 ++++
> include/linux/pci.h | 3 +
> 12 files changed, 503 insertions(+), 72 deletions(-)
>
>
> base-commit: f7982d85e136ba7e26b31a725c1841373f81f84a

This doesn't apply cleanly on v6.12-rc1, and
f7982d85e136ba7e26b31a725c1841373f81f84a isn't upstream yet. Where
is it? I guess it relies on some other series that hasn't been merged
yet?

Bjorn